1. Field of the Invention
This invention relates to material handling mechanisms and more particularly to an elevating type of material handling apparatus for demountable connection to the front end of an automotive road vehicle.
2. Description of the Prior Art
The loading and unloading of heavy materials on trucks, trailers and the like usually does not present a problem at a warehouse or other more or less permanent locations where such loading is often and frequently accomplished, in that conventional forklift trucks, conveyors and similar equipment is most often available at those sites. However, such is not the case in remote locations where loading and/or unloading is infrequently accomplished. Thus, at those remote locations the material handling is often accomplished by hand unless special arrangements are made to transport conventional material handling vehicles or equipment to those sites.
This material handling problem has long been recognized, and to the best of my knowledge, no completely satisfactory solution has yet been proposed.
For example, U.S. Pat. Nos. 2,910,203 and 3,186,571 both disclose forklift mechanisms mounted on the frame which extends rearwardly from the tractor cab of a tractor-trailer type of road vehicle. Those forklift mechanisms are very complex due to the fact that they are mounted at the same location where the trailer is coupled to the tractor. In addition to the complexity, the need for decoupling the tractor from the trailer prior to utilization of the forklift mechanism has contributed to the lack of commercial acceptance of those mechanisms.
In an attempt to provide a solution to this material handling problem, it was suggested in U.S. Pat. No. 3,272,287, that a forklift apparatus be carried on the front end of a tractor of a tractor-trailer road vehicle. This forklift apparatus is affixed between a pair of brackets which extend forwardly from the vehicle's frame, and is pivotably movable about an axis extending between those brackets so that the forklift may be tilted as required to properly level loads being elevated thereby. This prior art vehicular mounted forklift has several disadvantages and drawbacks. In the first place, the mounting technique employed is such that the forklift apparatus is, for all intents and purposes, an integral part of the vehicle and thus is most practically carried even when not needed. A second drawback results from the need to decouple the tractor from the trailer in order to handle materials in the trailer. Such decoupling is also advisable when the forklift mechanism is to be used to handle materials in another vehicle in that sufficient maneuverability is lacking when the tractor is coupled to a trailer. A further drawback exists in this specific prior art device, in that tilting of the forklift is accomplished by pivoting it about the previously described axis which is relatively low with respect to the height of the vehicle and such a low pivot axis seriously limits tilting movements of the forklift toward the vehicle due to the close proximity of the hood, radiator, and other front end components of the vehicle. A still further drawback of this prior art device is the relatively tall mast, or vertically stationary frame member in which the elevating equipment is mounted with that height constituting a visibility problem if the forklift apparatus is mounted on a vehicle other than one that is as tall as the trailer-tractor vehicle shown in this previously referenced U.S. Patent.
Therefore, a need exists for a materials handling mechanism for demountable attachment to an automotive road vehicle which overcomes some of the problems and shortcomings of the prior art.